RESUMEN
The efficiency of pristine graphene (GN) in the delivery process of the Favipiravir (FPV) anti-COVID-19 drug was herein revealed within the FPVâ¯GN complexes in perpendicular and parallel configurations in terms of the density functional theory (DFT) method. Adsorption energy findings unveiled that the parallel configuration of FPVâ¯GN complexes showed higher desirability than the perpendicular one, giving adsorption energy up to -15.95 kcal mol-1. This favorability could be interpreted as a consequence of the contribution of π-π stacking to the overall strength of the adsorption process in the parallel configuration. Frontier molecular orbitals (FMO) findings demonstrated the ability of the GN nanosheet to adsorb the FPV drug by the alteration in the EHOMO, ELUMO, and Egap values before and after the adsorption process. Based on Bader charge results, the FPV drug and GN sheet exhibited electron-donating and -accepting characters, respectively, which was confirmed by the negative sign of the computed charge transfer (Qt) values. The FPV(R)â¯T@GN complex showed the most desirable Qt value of -0.0377e, which was in synoptic with the adsorption energy pattern. Electronic properties of GN were also altered after the adsorption of the FPV drug in both configurations, with more observable changes in the parallel one. Interestingly, the Dirac point of the GN sheet coincided with the Fermi level after the adsorption process, indicating that the adsorption process unaffected the presence of the Dirac point. The occurrence of the adsorption process was also noticed by the existence of new bands and peaks in the band structure and DOS plots, respectively. Short recovery time rendered the GN nanosheet an efficient FPV drug delivery system. The obtained findings provide new insight into the biomedical applications of the GN sheet as a promising drug delivery system.
RESUMEN
MgO-ZrO2 mixed oxides prepared with different Mg/Zr atomic ratios (denoted as xMZ: where x is the atomic ratio of Mg/Zr) are investigated for the glucose isomerization to fructose in water at 95 °C. The highest fructose yield of 33 % is obtained over 0.76MZ with ≈74 % selectivity after 3â h. To gain insight into the structure-activity relationships, the prepared catalysts are characterized by N2 physisorption, XRD, FTIR and CO2 -TPD. The results indicate that the addition of MgO drastically changed the textual property of ZrO2 and increased the number of basic sites. The kinetic studies revealed that the Lewis basic sites (cus-O2- ) generated from the highly dispersed MgO are the active sites responsible for the enhanced isomerization activity. Notably, MZ is reusable for four runs without a significant decrease in catalyst activity. Accordingly, this study provides an easily prepared, cheap, and recyclable catalyst that may hold great potential for fructose production.
